That was literally in infinity war. It was a major part of the plot. Also we first saw it delivered to the collector in Thor: the dark world

So you didn't understand what I said?

What Steve's trying to say is that, despite it factually being there in Knowhere, we haven't seen the Reality Stone in Guardians of the Galaxy... or so we thought, as this video seems to suggest.

Exaclty, that was my point.